In-situ formation of layer-like Ag2MoO4 induced by high-temperature oxidation and its effect on the self-lubricating properties of NiCoCrAlYTa/Ag/Mo coatings

2021 ◽  
Vol 75 ◽  
pp. 164-173
Author(s):  
Enkang Hao ◽  
Yulong An ◽  
Jie Chen ◽  
Xiaoqin Zhao ◽  
Guoliang Hou ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
The Self ◽  
Temperature Oxidation ◽  
In Situ Formation ◽  
Lubricating Properties

scholarly journals High-temperature oxidation resistance of VCps-reinforced Fe-matrix composites using an in-situ reaction

AIP Advances ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 015319
Author(s):  
Pinghu Chen ◽  
Ruiqing Li ◽  
Ripeng Jiang ◽  
Songsheng Zeng ◽  
Yun Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Matrix Composites ◽  
Temperature Oxidation ◽  
In Situ Reaction

In Situ Measurement of the Phase Transformation Behavior of Al2O3 Scale during High-Temperature Oxidation using Synchrotron Radiation

2011 ◽  
Vol 696 ◽  
pp. 63-69 ◽  
Author(s):  
Shigenari Hayashi ◽  
Isao Saeki ◽  
Yoshitaka Nishiyama ◽  
Takashi Doi ◽  
Shoji Kyo ◽  
...  
Keyword(s):  
High Temperature ◽  
Synchrotron Radiation ◽  
High Temperature Oxidation ◽  
Structural Changes ◽  
Lattice Parameter ◽  
Transformation Behavior ◽  
Initial Oxidation ◽  
Temperature Oxidation ◽  
Diffraction Peaks

Very thin Fe-coatings, ~50nm, were found to suppress metastable Al2O3 formation on Fe-50Al and Ni-50Al alloys in our previous study. The authors proposed a mechanism whereby α-Al2O3 precipitates from the Al-saturated Fe2O3, which was formed during initial oxidation, since α-Al2O3 and α-Fe2O3 have isomorphous structures. In order to confirm the proposed mechanism, in-situ measurements were made of structural changes in the oxide scales formed on FeAl with and without Fe coating during heating and subsequent isothermal high temperature oxidation by synchrotron radiation with a two-dimensional X-ray detector. Diffraction peaks from Fe2O3 were initially observed at around 350°C on Fe-coated samples. The lattice parameter of the Fe2O3 initially increased linearly due to thermal expansion, but then rapidly decreased due to the formation of a solid solution of Fe2O3-Al2O3. α-Al2O3 started to appear at around 800°C, but no peaks from metastable Al2O3 were observed. The diffraction peaks from the α-Al2O3 on Fe-coated samples consisted of two distinct peaks, indicating that the α-Al2O3 had two different lattice parameters. These results suggest that the α-Al2O3 was formed not only by precipitation from the Al-saturated Fe2O3, but also by oxidation of Al in the substrate.

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